(1) Field of the Invention
This invention relates to a wireless communication apparatus and, more particularly, to a wireless communication apparatus for connecting a plurality of wired networks with wireless communication.
(2) Description of the Related Art
Recently there has been growing data communication between electronic devices in wireless Local Area Networks (LAN). The wireless LAN communication system is setup with an adhoc network, an infrastructure network, and/or a wireless distribution system. The ad hoc network is a peer-to-peer connection of only wireless terminals. The infrastructure network is one in which one access point and terminals constitute a wireless network and a plurality of access points are linked by wired connection. The wireless distribution system is a wireless LAN connection of access points.
If a wired connection cannot be established as a LAN connection between two office buildings, both the infrastructure network and the wireless distribution system may be used (hereinafter, this is referred to as a combined technique). By using this technique, the wired LANs of the two office buildings can be connected with a wireless LAN.
The combined technique uses access points to link wired LAN networks by a wireless connection, the wired LAN networks each composed of terminals such as personal computers. Terminals on the different wired LANs can communicate with each other via the terminal access points of the wired LANs.
In wireless communication, third parties can intercept communication. In case of interception of communication, data should be made confidential with encryption before transmission. Wireless LANs ensure security with the Wired Equivalent Privacy (WEP) encryption technology which is defined by IEEE802.11.
To offer secured data communication over the infrastructure network, an authentication method in a wireless LAN has been proposed, in which the Media Access Control (MAC) addresses of client terminals are stored in an authentication server and when a terminal requests an access point for authentication, the access point sends the authentication server the terminal's MAC address information to make the authentication server perform the authentication process (for example, refer to Japanese Unexamined Patent 2001-111544 (Paragraph [0027]-[0033], FIG. 1).
The WEP encryption technology, however, allows a third party to successively intercept encrypted data and assume an encryption key being used in the communication area of the wireless LAN from the data. That is, this technology has a data leakage problem.